Integumentary System- pg. 5 Body Membranes- 1) Cutaneous (skin) & Mucosa 2) Serosa 3) Synovial Integumentary System

Body Membranes-Epithelial- Cutaneous (skin) & Mucosa

Epithelial & Connective- Serosa- parietal and visceral

Connective- synovial (joints)

Skin

Skin Function Protects against: bumps, chemicals, bacteria, sun, temperature and desiccation Aids in body heat control Excretes urea & uric acid Synthesizes vitamin D

Structure- Epidermis- epithelial tissue up to 5 different type layers

Stratum basale- (bottom) Closest to the dermis Well fed keratinocytes Contains melanocytes Produce melanin that shields against sun damage

Stratum spinosum-2 nd (bottom) Stratum granulose-3rd Stratum lucidum-4th Stratum corneum-top layers of thick dead cells, filled with keratin

Dermis Top region = papillary layer with dermal papillae, push up epidermis = fingerprints Deeper region = reticular layer

Dermis contains blood vessels, sweat and oil glands, pressure receptors, (pacinian) rich nerve supply, hair follicles

Hypodermis- subcutaneous, adipose tissue anchors skin

Skin color- everyone has the same number of melanocytes, but some produce more/less melanin

Things that affect skin color: Melanin- yellow, red, brown Carotene- yellow pigment Hemoglobin- redness Cyanosis- blue (lack of O2) Pallor- pale Jaundice- yellow, liver problems Bruise- hematoma

Glands in Skin All exocrine (ducts) Sebaceous- oil, deposit sebum into a duct that opens to a hair follicle or surface Acne: Blockage= whitehead -> blackhead -> pimple

Sudoriferous Sweat glands (2.5 million) Eccrine- all over, empty at surface, temperature regulation Apocrine- axillary and genital area, form at adolescence, empty into hair follicles, can mix with bacteria = smell Cerumenous- earwax (cerumen)

Hair Fastest growing cells living in the matrix, dead cells in shaft. Surface arrector pili muscle- attaches the hair to dermis Contracted = skin dimples

Nails- living matrix, rest is nonliving bed and free edge

Burns

1 st degree- red, swollen, pain- epidermis damaged

2 nd degree- red, pain, blister, epidermis & upper dermis

3 rd degree- gray, white, black, no pain, entire skin, thick

Problems: Infection Airway obstruction (face) Scar tissue

Rule Of Nines Calculates the % burned

Neoplasms -Abnormal growths- -Most are benign (not cancer)

Basal Cell Carcinoma From Stratum basale, surgically removed- curable

Squamous Cell Carcinoma From Stratum spinosum- grows rapidly, curable

Malignant Melanoma From melanocytes, can be deadly A- asymmetry B- border irregularity C- color D- diameter-> 6mm (eraser)

Other Problems

Infections: Athlete’s Foot- fungus Boils bacterial infection Cold Sores- Herpes S Virus Contact dermatitis- chemical (poison ivy) Impetigo- staphylococcus

Psoriasis- auto immune Striae- stretch marks Flexure lines- creases over joints Blister- epidermis and dermis separate Lines of Cleavage- tension lines

Development Fetus- – 5-6 months-lanugo (fine, soft hair)

Birth Vernix caseosa- cheesy cover lubricates skin Milia- oil glands/white spots

Adolescence- Oily skin Oily hair Acne, Axillary hair and sweat

Old Age- Subcutaneous fat decreases Decreased oil production Less elastin Less hair Less Langerhorn cells (immunity) Less melanin